Assessing Safety of Anticoagulation for Atrial Fibrillation in Patients with Cirrhosis: A Real-World Outcomes Study.

AIMS: In patients with atrial fibrillation (AF) and stroke risk factors, randomized trials have demonstrated that anticoagulation decreases the risk of ischemic stroke. However, all trials to date have excluded patients with significant liver disease, leaving guidelines to extrapolate recommendations. We aim to evaluate the impact of anticoagulation on safety events in patients with AF and cirrhosis. METHODS AND RESULTS: In this retrospective cohort study, we obtained de-identified health record data to extract anticoagulation strategy, comorbidities, prescriptions, lab values, and procedures for a cohort of patients with cirrhosis who develop AF. After selecting a propensity matched population to match patients with various anticoagulation strategies, we tracked data on outcomes for death, transfusion requirements, hospital and ICU admissions. After propensity score weighting and multivariable adjustment, anticoagulation strategy was associated with increased hospital admission count (OR = 1.74 per admission, P < .001), binary risk of hospital admission (OR = 1.54, P = .010) and risk of ICU admission (OR = 1.41, P = .047). We detected no significant differences in mortality, transfusion of blood products, or average length of stay. Direct oral anticoagulant (DOAC) prescriptions were associated with increased binary risk of hospital admission compared to warfarin prescriptions. In a third comparison, DOAC strategy alone was associated with increased hospital admission count (OR = 1.41 per admission, P < .001) and binary risk of hospital admission (OR = 1.52, P = .038) compared to no anticoagulation strategy. CONCLUSION: Anticoagulation strategy in patients with cirrhosis and AF was associated with increased rate of hospital admission and ICU admission but not associated with increased risk of mortality or transfusion requirement.

Early diastolic heart sounds caused by the atrial kick.

An 81-year-old male with a history of coronary artery disease, hypertension, paroxysmal atrial fibrillation and chronic kidney disease presents with asymptomatic bradycardia. Examination was notable for an early diastolic heart sound. 12-lead electrocardiogram revealed sinus bradycardia with a markedly prolonged PR interval and second-degree atrioventricular block, type I Mobitz. We review the differential diagnosis of early diastolic heart sounds and present a case of Wenckebach associated with a variable early diastolic sound on physical exam.

Utility of preoperative troponin I to predict mortality in adult liver transplant recipients: Revisiting pretransplant cardiac risk in the current MELD-allocation era.

BACKGROUND: Preoperative risk assessment in liver transplant (LT) candidates, particularly related to cardiac risk, is an area of intense interest for transplant clinicians. Various cardiac testing methods are employed by transplant centers to characterize cardiac risk. Serum troponin is an established method for the detection of myocardial injury in a wide variety of clinical settings. Preoperative troponin screening has been reported to predict postoperative cardiac events and mortality in various surgical patient populations, however, the utility of preoperative troponin to predict posttransplant outcomes in current LT candidate populations requires further investigation. METHODS: We performed a prospective blinded study in a cohort of 275 consecutive LT recipients at a single transplant center to determine if preoperative serum troponin I (TnI) was predictive for postoperative 1-year mortality. RESULTS: Abnormal preoperative TnI levels (>.1 ng/mL) were found in 38 patients (14%). One-year mortality occurred in 19 patients (7%). There was no significant difference in mortality between patients with normal and abnormal troponin levels. Additionally, we found that there was no significant difference in early postoperative major adverse cardiac events between patient groups. CONCLUSIONS: Contrary to previous reports, elevated preoperative TnI was not significantly predictive of posttransplant mortality in LT recipients at our institution.

Simultaneous vs Staged Cardiac Intervention in High-Acuity Liver Transplant.

This cohort study examines mortality, survival, and other outcomes among adults who underwent combined cardiac surgery and liver transplant, coronary revascularization prior to liver transplant, or isolated liver transplant.

Fractional Flow Reserve in End-Stage Liver Disease.

Fractional flow reserve (FFR) determines the functional significance of epicardial stenoses assuming negligible venous pressure (Pv) and microvascular resistance. However, these assumptions may be invalid in end-stage liver disease (ESLD) because of fluctuating Pv and vasodilation. Accordingly, all patients with ESLD who underwent right-sided cardiac catheterization and coronary angiography with FFR as part of their orthotopic liver transplantation evaluation between 2013 and 2018 were included in the present study. Resting mean distal coronary pressure (Pd)/mean aortic pressure (Pa), FFR, and Pv were measured. FFR accounting for Pv (FFR - Pv) was defined as (Pd - Pv)/(Pa - Pv). The hyperemic effect of adenosine was defined as resting Pd/Pa - FFR. The primary outcome was all-cause mortality at 1 year. In 42 patients with ESLD, 49 stenoses were interrogated by FFR (90% were <70% diameter stenosis). Overall, the median model for ESLD score was 16.5 (10.8 to 25.5), FFR was 0.87 (0.81 to 0.94), Pv was 8 mm Hg (4 to 14), FFR-Pv was 0.86 (0.80 to 0.94), and hyperemic effect of adenosine was 0.06 (0.02 to 0.08). FFR-Pv led to the reclassification of 1 stenosis as functionally significant. There was no significant correlation between the median model for ESLD score and the hyperemic effect of adenosine (R = 0.10). At 1 year, 13 patients had died (92% noncardiac in etiology), and patients with FFR ≤0.80 had significantly higher all-cause mortality (73% vs 17%, p = 0.001. In conclusion, in patients with ESLD who underwent orthotopic liver transplantation evaluation, Pv has minimal impact on FFR, and the hyperemic effect of adenosine is preserved. Furthermore, even in patients with the predominantly angiographically-intermediate disease, FFR ≤0.80 was an independent predictor of all-cause mortality.

Biomolecules Orchestrating Cardiovascular Calcification.

Vascular calcification, once considered a degenerative, end-stage, and inevitable condition, is now recognized as a complex process regulated in a manner similar to skeletal bone at the molecular and cellular levels. Since the initial discovery of bone morphogenetic protein in calcified human atherosclerotic lesions, decades of research have now led to the recognition that the regulatory mechanisms and the biomolecules that control cardiovascular calcification overlap with those controlling skeletal mineralization. In this review, we focus on key biomolecules driving the ectopic calcification in the circulation and their regulation by metabolic, hormonal, and inflammatory stimuli. Although calcium deposits in the vessel wall introduce rupture stress at their edges facing applied tensile stress, they simultaneously reduce rupture stress at the orthogonal edges, leaving the net risk of plaque rupture and consequent cardiac events depending on local material strength. A clinically important consequence of the shared mechanisms between the vascular and bone tissues is that therapeutic agents designed to inhibit vascular calcification may adversely affect skeletal mineralization and vice versa. Thus, it is essential to consider both systems when developing therapeutic strategies.

Takayasu Arteritis With Extensive Cardiovascular, Neurovascular, and Mesenteric Involvement.

Takayasu arteritis is a rare large vessel vasculitis with an incidence of 1 to 3 per million. This disease typically involves the aorta and its primary branches but has been found to involve the coronary arteries in 7% to 9% of cases. We highlight the need for prompt diagnosis and treatment. (Level of Difficulty: Beginner.).

Significance of Coronary Artery Calcium Found on Non-Electrocardiogram-Gated Computed Tomography During Preoperative Evaluation for Liver Transplant.

Guidelines to evaluate patients for coronary artery disease (CAD) during preoperative evaluation for orthotopic liver transplantation (OLT) are conflicting. Cardiac catheterization is not without risk in patients with end-stage liver disease. No study to date has looked at the utility of non-electrocardiogram-gated chest computed tomography (CT) in the preliver transplant population. Our hypothesis was that coronary artery calcium scores (CACSs) from chest CT scans ordered during the liver transplant workup can identify patients who would benefit from invasive angiography. Nine hundred and fifty-three patients who underwent coronary angiography as part of their OLT workup were considered. Charts were randomly selected and reviewed for the presence of a chest CT performed before coronary angiography during the OLT workup. Agatston and Weston scores were calculated. CACS results were compared with coronary angiography findings. Nine of 54 patients were found to have obstructive CAD by angiography. Receiver-operating characteristic analysis demonstrated that an Agatston score of 251 and a Weston score of 6 maximized sensitivity and specificity for detection of obstructive coronary disease. An Agatston score <4 or Weston score <2 excluded the presence of obstructive CAD; using these thresholds, 13 patients (24%) or 15 patients (28%), respectively, could have theoretically avoided catheterization without missing significant CAD. In conclusion, our data identify the strength of CACS in ruling out coronary disease in patients being evaluated for OLT. Calcium scoring from non-electrocardiogram-gated CT studies may be integrated into preoperative algorithms to rule out obstructive CAD and help avoid invasive angiography in this high-risk population.

Incidence, Predictors, and Outcomes of New-Onset Left Ventricular Systolic Dysfunction After Orthotopic Liver Transplantation.

BACKGROUND: Adverse cardiovascular events after liver transplantation (LT) are relatively common and are a significant source of early mortality. Although new-onset systolic dysfunction after LT is a reported phenomenon, there is little data regarding its incidence, risk factors, and outcomes. METHODS AND RESULTS: This single-center retrospective study included all adult patients from January 2002 to March 2015 with deceased-donor LT and available preoperative transthoracic echocardiograms (TTEs). In total, 1,760 patients were included in the study, 602 (34.2%) of whom had a postoperative TTE. The primary end point was development of new-onset cardiomyopathy, defined as a new left ventricular ejection fraction (LVEF) of <40% within 180days of transplant. Sixty-nine (11.4%) of the patients who received post-LT TTE had a reduction in LVEF to <40% within 6 months. Clinical parameters of donor and recipient did not show significant impact on development of post-LT LV systolic dysfunction (LVSD). Presence of wall motion abnormalities (P = .004) on preoperative TTE was predictive of development of post-LT LVSD. These patients did not have longer hospitalizations, but they had worse survival. CONCLUSIONS: Post-LT LV systolic dysfunction occurs at higher rates than previously suspected and may develop more frequently in patients with underlying cardiac structural abnormalities, which appear to adversely affect post-LT survival.

Liver transplantation in highest acuity recipients: identifying factors to avoid futility.

OBJECTIVE: To identify medical predictors of futility in recipients with laboratory Model of End-Stage Liver Disease (MELD) scores of 40 or more at the time of orthotopic liver transplantation (OLT). BACKGROUND: Although the survival benefit for transplant patients with the highest MELD scores is indisputable, the medical and economic effort to bring these highest acuity recipients through OLT presents a major challenge for every transplant center. METHODS: This study was undertaken to analyze outcomes in patients with MELD scores of 40 or more undergoing OLT during the period February 2002 to December 2010. The analysis was focused on futile outcome (3-month or in-hospital mortality) and long-term posttransplant outcome. Independent predictors of futility and failure-free survival were identified and a futility risk model was created. RESULTS: During the study period, 1522 adult cadaveric OLTs were performed, and 169 patients (13%) had a MELD score of 40 or more. The overall 1, 3, 5, and 8-year patient survivals were 72%, 64%, 60%, and 56%. Futile outcome occurred in 37 patients (22%). MELD score, pretransplant septic shock, cardiac risk, and comorbidities were independent predictors of futile outcome. Using all 4 factors, the futility risk model had a good discriminatory ability (c-statistic 0.75). Recipient age per year, life-threatening postoperative complications, hepatitis C, and metabolic syndrome were independent predictors for long-term survival in nonfutile patients (Harrels c-statistic 0.72). CONCLUSIONS: Short- and long-term outcomes of recipients with MELD scores of 40 or more are primarily determined by disease-specific factors. Cardiac risk, pretransplant septic shock, and comorbidities are the most important predictors and can be used for risk stratification in these highest acuity recipients.

Aspergillus fumigatus vegetation of a prosthetic aortic root graft with mycotic aneurysm and subarachnoid hemorrhage.

A 58-year-old woman with a history of Bentall aortic graft and bioprosthetic aortic valve replacement 3 months prior to admission, presented with headache and fever. Imaging yielded a large obstructive filling defect in the ascending aorta, a subarachnoid hemorrhage, and a mycotic aneurysm. Intraoperative specimens grew Aspergillus fumigatus, and despite aggressive measures the patient died. Aspergillus infections of prosthetic vascular grafts are rare surgical complications and are difficult to diagnose given the low incidence of positive microbiology cultures and the long median time between surgery and diagnosis. Treatment has consisted of antifungal and surgical treatment, although mortality remains high.

Accuracy of stress myocardial perfusion imaging to diagnose coronary artery disease in end stage liver disease patients.

Patients with end-stage liver disease (ESLD) who also have underlying coronary artery disease (CAD) may be at increased risk for undergoing hemodynamically challenging orthotopic liver transplantation. Noninvasive single-photon emission computed tomographic (SPECT) imaging is often used to determine whether a patient with ESLD has unsuspected CAD. The objective of this study was to determine the accuracy of SPECT imaging for detection of CAD in patients with ESLD. Patients with ESLD who underwent coronary angiography and SPECT imaging before orthotopic liver transplantation were analyzed retrospectively. The predictive accuracy of clinical risk factors was calculated and compared to the results of SPECT imaging. There were 473 SPECT imaging studies. Adenosine SPECT imaging had a sensitivity of 62%, specificity of 82%, positive predictive value of 30%, and negative predictive value of 95% for diagnosing severe CAD. Regadenoson SPECT imaging had a sensitivity of 35%, specificity of 88%, positive predictive value of 23%, and negative predictive value of 93% for diagnosing severe CAD. The accuracy of a standard risk factor analysis showed no statistical difference in predicting CAD compared with adenosine (sensitivity McNemar's p = 0.48, specificity McNemar's p = 1.00) or regadenoson (sensitivity McNemar's p = 0.77, specificity McNemar's p = 1.00) SPECT studies. In conclusion, the 2 pharmaceutical agents had low sensitivity but high specificity for diagnosing CAD. However, because the sensitivity of the test is low, the chances of missing patients with ESLD with CAD is high, making SPECT imaging an inaccurate screening test. A standard risk factor analysis as a predictor for CAD in patients with ESLD is less expensive, has no radiation exposure, and is as accurate as SPECT imaging.

A role for NADPH oxidase 4 in the activation of vascular endothelial cells by oxidized phospholipids.

Previous studies from our group have demonstrated that oxidized 1-palmitoyl-2-arachidonyl-sn-glycerol-3-phosphocholine (Ox-PAPC) activates over 1000 genes in human aortic endothelial cells (HAECs). Prominent among these are genes regulating inflammation, cholesterol homeostasis, antioxidant enzymes, and the unfolded protein response. Previous studies from our lab and others suggested that transcriptional regulation by Ox-PAPC may be controlled, at least in part, by reactive oxygen species. We now present evidence that Ox-PAPC activation of NADPH oxidase 4 (NOX4) is responsible for the regulation of two of these important groups of genes: those controlling inflammation and those involved in sterol regulation. Our data demonstrate that Ox-PAPC increases reactive oxygen species formation in HAECs as seen by DCF fluorescence. NOX4 is the major molecule responsible for this increase because downregulation of NOX4 and its components (p22(phox) and rac1) blocked the Ox-PAPC effect. Our data show that Ox-PAPC did not change NOX4 transcription levels but did induce recruitment of rac1 to the membrane for NOX4 activation. We present evidence that vascular endothelial growth factor receptor 2 (VEGFR2) activation is responsible for rac1 recruitment to the membrane. Finally, we demonstrate that knockdown of NOX4 and its components rac1 and p22(phox) decreases Ox-PAPC induction of inflammatory and sterol regulatory genes, but does not affect Ox-PAPC transcriptional regulation of other genes for antioxidants and the unfolded protein response. In summary, we have identified a VEGFR2/NOX4 regulatory pathway by which Ox-PAPC controls important endothelial functions.

Ox-PAPC activation of PMET system increases expression of heme oxygenase-1 in human aortic endothelial cell.

Oxidized-1-palmitoyl-2-arachidonyl-sn-glycerol-3-phosphocholine (Ox-PAPC) has been demonstrated to accumulate in atherosclerotic lesions and regulates expression of more than 1,000 genes in human aortic endothelial cell (HAEC). Among the most highly induced is heme oxygenase-1 (HO-1), a cell-protective antioxidant enzyme, which is sensitively induced by oxidative stress. To identify the pathway by which Ox-PAPC induces HO-1, we focused on the plasma membrane electron transport (PMET) complex, which contains ecto-NADH oxidase 1 (eNOX1) and NADPH:quinone oxidoreductase 1 (NQO1) and affects cellular redox status by regulating levels of NAD(P)H. We demonstrated that Ox-PAPC and its active components stimulated electron transfer through the PMET complex in HAECs from inside to outside [as determined by extracellular 2-(4-iodophenyl)-3-(44-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-1) reduction] and from outside to inside of the cell (as determined by intracellular NBT reduction). Chemical inhibitors of PMET system and siRNAs to PMET components (NQO1 and eNOX1) significantly decreased HO-1 induction by Ox-PAPC. We present evidence that Ox-PAPC activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in HAEC plays an important role in the induction of HO-1 and PMET inhibitors blocked Nrf2 activation by Ox-PAPC. We hypothesized that PMET activation by Ox-PAPC causes intracellular NAD(P)H depletion, which leads to the increased oxidative stress and HO-1 induction. Supporting this hypothesis, cotreatment of cells with exogenous NAD(P)H and Ox-PAPC significantly decreased oxidative stress and HO-1 induction by Ox-PAPC. Taken together, we demonstrated that the PMET system in HAEC plays an important role in the regulation of cellular redox status and HO-1 expression by Ox-PAPC.

Altered proteome biology of cardiac mitochondria under stress conditions.

Myocardial ischemia-reperfusion induces mitochondrial dysfunction and, depending upon the degree of injury, may lead to cardiac cell death. However, our ability to understand mitochondrial dysfunction has been hindered by an absence of molecular markers defining the various degrees of injury. To address this paucity of knowledge, we sought to characterize the impact of ischemic damage on mitochondrial proteome biology. We hypothesized that ischemic injury induces differential alterations in various mitochondrial subcompartments, that these proteomic changes are specific to the severity of injury, and that they are important to subsequent cellular adaptations to myocardial ischemic injury. Accordingly, an in vitro model of cardiac mitochondria injury in mice was established to examine two stress conditions: reversible injury (induced by mild calcium overload) and irreversible injury (induced by hypotonic stimuli). Both forms of injury had a drastic impact on the proteome biology of cardiac mitochondria. Altered mitochondrial function was concomitant with significant protein loss/shedding from the injured organelles. In the setting of mild calcium overload, mitochondria retained functionality despite the release of numerous proteins, and the majority of mitochondria remained intact. In contrast, hypotonic stimuli caused severe damage to mitochondrial structure and function, induced increased oxidative modification of mitochondrial proteins, and brought about detrimental changes to the subproteomes of the inner mitochondrial membrane and matrix. Using an established in vivo murine model of regional myocardial ischemic injury, we validated key observations made by the in vitro model. This preclinical investigation provides function and suborganelle location information on a repertoire of cardiac mitochondrial proteins sensitive to ischemia reperfusion stress and highlights protein clusters potentially involved in mitochondrial dysfunction in the setting of ischemic injury.

Systematic characterization of the murine mitochondrial proteome using functionally validated cardiac mitochondria.

Mitochondria play essential roles in cardiac pathophysiology and the murine model has been extensively used to investigate cardiovascular diseases. In the present study, we characterized murine cardiac mitochondria using an LC/MS/MS approach. We extracted and purified cardiac mitochondria; validated their functionality to ensure the final preparation contains necessary components to sustain their normal function; and subjected these validated organelles to LC/MS/MS-based protein identification. A total of 940 distinct proteins were identified from murine cardiac mitochondria, among which, 480 proteins were not previously identified by major proteomic profiling studies. The 940 proteins consist of functional clusters known to support oxidative phosphorylation, metabolism, and biogenesis. In addition, there are several other clusters, including proteolysis, protein folding, and reduction/oxidation signaling, which ostensibly represent previously under-appreciated tasks of cardiac mitochondria. Moreover, many identified proteins were found to occupy other subcellular locations, including cytoplasm, ER, and golgi, in addition to their presence in the mitochondria. These results provide a comprehensive picture of the murine cardiac mitochondrial proteome and underscore tissue- and species-specification. Moreover, the use of functionally intact mitochondria insures that the proteomic observations in this organelle are relevant to its normal biology and facilitates decoding the interplay between mitochondria and other organelles.

Past and present course of cardioprotection against ischemia-reperfusion injury.

Despite tremendous advances in cardiovascular research and clinical therapy, ischemic heart disease remains the leading cause of serious morbidity and mortality in western society and is growing in developing countries. For the past 5 decades, many scientists have studied the pathophysiology of myocardial ischemia-reperfusion (I/R) injury leading to infarction. With the exception of reperfusion therapy, attempts to salvage the myocardium during an acute myocardial infarction showed disappointing results in directly decreasing infarct size. Nevertheless, the phenomena of ischemic preconditioning and ischemic postconditioning show a consistent and robust cardioprotective effect in every used experimental animal model. As a result, many studies have focused on the intracellular protective signaling pathways that are involved in preconditioning and postconditioning. More recently, it has been suggested that components of the reperfusion injury salvage kinases pathway, protein kinase B, and the extracellular signal-regulated kinases can induce cardioprotection against I/R injury when they are activated during the postischemic reperfusion period. In addition, inhibition of mitochondrial permeability transition during postischemic reperfusion also shows a strong cardioprotective effect against I/R injury. The present mini-review highlights a short summary of the historical and present course of research into cardioprotection against myocardial I/R injury.